2024-01-08 21:20:03

by Ludvig Pärsson

Subject: [PATCH net] ethtool: netlink: Add missing ethnl_ops_begin/complete

Accessing an ethernet device that is powered off or clock gated might
cause the CPU to hang. Add ethnl_ops_begin/complete in
ethnl_set_features() to protect against this.

Signed-off-by: Ludvig Pärsson <[email protected]>
---
net/ethtool/features.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/ethtool/features.c b/net/ethtool/features.c
index a79af8c25a07..b6cb101d7f19 100644
--- a/net/ethtool/features.c
+++ b/net/ethtool/features.c
@@ -234,17 +234,20 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
dev = req_info.dev;

rtnl_lock();
+ ret = ethnl_ops_begin(dev);
+ if (ret < 0)
+ goto out_rtnl;
ethnl_features_to_bitmap(old_active, dev->features);
ethnl_features_to_bitmap(old_wanted, dev->wanted_features);
ret = ethnl_parse_bitset(req_wanted, req_mask, NETDEV_FEATURE_COUNT,
tb[ETHTOOL_A_FEATURES_WANTED],
netdev_features_strings, info->extack);
if (ret < 0)
- goto out_rtnl;
+ goto out_ops;
if (ethnl_bitmap_to_features(req_mask) & ~NETIF_F_ETHTOOL_BITS) {
GENL_SET_ERR_MSG(info, "attempt to change non-ethtool features");
ret = -EINVAL;
- goto out_rtnl;
+ goto out_ops;
}

/* set req_wanted bits not in req_mask from old_wanted */
@@ -281,6 +284,8 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
if (mod)
netdev_features_change(dev);

+out_ops:
+ ethnl_ops_complete(dev);
out_rtnl:
rtnl_unlock();
ethnl_parse_header_dev_put(&req_info);

---
base-commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a
change-id: 20240108-etht2-2b2454e837e7

Best regards,
--
Ludvig Pärsson <[email protected]>

2024-01-11 11:30:40

by Paolo Abeni

Subject: Re: [PATCH net] ethtool: netlink: Add missing ethnl_ops_begin/complete

On Mon, 2024-01-08 at 16:17 +0100, Ludvig Pärsson wrote:
> Accessing an ethernet device that is powered off or clock gated might
> cause the CPU to hang. Add ethnl_ops_begin/complete in
> ethnl_set_features() to protect against this.
>

We need a suitable Fixes tag here

> Signed-off-by: Ludvig Pärsson <[email protected]>
> ---
> net/ethtool/features.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/net/ethtool/features.c b/net/ethtool/features.c
> index a79af8c25a07..b6cb101d7f19 100644
> --- a/net/ethtool/features.c
> +++ b/net/ethtool/features.c
> @@ -234,17 +234,20 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
> dev = req_info.dev;
>
> rtnl_lock();
> + ret = ethnl_ops_begin(dev);
> + if (ret < 0)
> + goto out_rtnl;

You should likely follow-up on net-next only converting
ethnl_set_features to ethnl_default_set_doit.

Cheers,

Paolo